<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      // = 是赋值
      var a = 1
      a = 2
      console.log('a', a) // 2

      // += -= /= *= 是在自身上再进行+ - / *
      var b = 1
      b += 1
      console.log('b', b) // 2

      var c = 1
      c -= 1
      console.log('c', c) // 0

      var d = 4
      d /= 2
      console.log('d', d) // 2

      var e = 1
      e *= 4
      console.log('e', e) // 4
    </script>
  </body>
</html>
